1. Field of the Invention
The present invention relates to an audiovisual communications terminal apparatus which is adapted for use to conduct an audiovisual teleconference. More particularly, the present invention is directed to an audiovisual communications terminal apparatus which is adapted for interconnection with at least another audiovisual communications terminal apparatus by a communications medium to form a teleconferencing network so that the teleconferencing users can both see and hear each other.
2. Description of Related Art
The public's desire to communicate is exemplified by the proliferation of telephone service since the invention of the telephone by Alexander Graham Bell. For decades, the public has been able to effectively communicate with one another through inexpensive use of the telephone system. In response to the public's desire for enhanced telephone service, several companies have developed audiovisual telephone services so that two or more parties can conduct an audiovisual teleconference.
One type of service developed by AT&T provides a telephone with a video monitor. Typically, this video telephone is installed in a variety of public locations. This service, however, is not widely available and it is, therefore, inconvenient for customers to use.
AT&T developed a "picture" telephone for its customers. The picture portion of this telephone service, of course, could only be used by the calling party if the called party also had a "picture" telephone. The pictures are transmitted between the "picture" telephones through conventional telephone lines on a H.324 analog video communications standard. This results in the sending "picture" telephone producing three to five video frames per second to the receiving "picture" telephone. Three to five framesper second displayed on the video monitor does not produce a continuous picture as provided, for example, by a television. In fact, the picture on the picture monitor appears to be depicted in short intervals producing an old fashion "nickelodeon" effect. This is irritating to a viewer because the viewer is conditioned to viewing a continuous motion picture. In comparison, a television depicts thirty frames of pictures per second which results in a continuous, albeit perceived, true motion picture. Because of these drawbacks, the "picture" telephone is not widely adopted by the general public.
A desktop video system has made it possible for private individuals to participate in audiovisual teleconferencing. However, the products and services associated with private audiovisual teleconferencing requires service fees and an investment in equipment that substantially exceed the cost of ordinary telephone services. Thus, desktop video systems are not attractive to the consumer who would only be a casual or incidental user of it.
Also, several companies provide audiovisual teleconferencing services primarily to businesses. The cost for audiovisual teleconferencing services for businesses is high. However, such cost is justified when considering the cost of travel, time value of the business person and other expenses incurred while away from the office. Therefore, although there is a demand for audiovisual teleconferencing services in businesses, terminal equipment for this purpose remains concentrated in a relatively small business market.
There is a need in the marketplace to provide a lowcost audiovisual teleconferencing network for private individuals. It would be advantageous if the audiovisual communications terminal apparatus can be used with a H.320 or a H.323 digital video communications standard and a H.324 analog video communications standard. There is also a need in the industry to provide high quality teleconferencing video service, particularly as compared to prior "picture" telephones. It would be advantageous if the audiovisual communications terminal apparatus could be portable so that it could be used in the home as well as for business.